diff --git a/block/disk-events.c b/block/disk-events.c
index a75931ff5da4e35ef14e1df668bef15651a8e82d..04c52f3992eda4140e4e538767d9e4ef33568f90 100644
--- a/block/disk-events.c
+++ b/block/disk-events.c
@@ -190,6 +190,9 @@ static void disk_check_events(struct disk_events *ev,
 
 	spin_unlock_irq(&ev->lock);
 
+	if (events & DISK_EVENT_MEDIA_CHANGE)
+		inc_diskseq(disk);
+
 	/*
 	 * Tell userland about new events.  Only the events listed in
 	 * @disk->events are reported, and only if DISK_EVENT_FLAG_UEVENT
diff --git a/block/genhd.c b/block/genhd.c
index 38f053074159785f6f3b1697f7f86bcca18d6082..ceb08af72c1a27547bae6f04e5ef769b274c9754 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -29,6 +29,23 @@
 
 static struct kobject *block_depr;
 
+/*
+ * Unique, monotonically increasing sequential number associated with block
+ * devices instances (i.e. incremented each time a device is attached).
+ * Associating uevents with block devices in userspace is difficult and racy:
+ * the uevent netlink socket is lossy, and on slow and overloaded systems has
+ * a very high latency.
+ * Block devices do not have exclusive owners in userspace, any process can set
+ * one up (e.g. loop devices). Moreover, device names can be reused (e.g. loop0
+ * can be reused again and again).
+ * A userspace process setting up a block device and watching for its events
+ * cannot thus reliably tell whether an event relates to the device it just set
+ * up or another earlier instance with the same name.
+ * This sequential number allows userspace processes to solve this problem, and
+ * uniquely associate an uevent to the lifetime to a device.
+ */
+static atomic64_t diskseq;
+
 /* for extended dynamic devt allocation, currently only one major is used */
 #define NR_EXT_DEVT		(1 << MINORBITS)
 static DEFINE_IDA(ext_devt_ida);
@@ -1252,6 +1269,8 @@ struct gendisk *__alloc_disk_node(int minors, int node_id)
 	disk_to_dev(disk)->class = &block_class;
 	disk_to_dev(disk)->type = &disk_type;
 	device_initialize(disk_to_dev(disk));
+	inc_diskseq(disk);
+
 	return disk;
 
 out_destroy_part_tbl:
@@ -1352,3 +1371,8 @@ int bdev_read_only(struct block_device *bdev)
 	return bdev->bd_read_only || get_disk_ro(bdev->bd_disk);
 }
 EXPORT_SYMBOL(bdev_read_only);
+
+void inc_diskseq(struct gendisk *disk)
+{
+	disk->diskseq = atomic64_inc_return(&diskseq);
+}
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 13b34177cc8502622dcf6c7c01009a10b5303a47..140c028845af07c45e5d000926d3be28928fc141 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -172,6 +172,7 @@ struct gendisk {
 	int node_id;
 	struct badblocks *bb;
 	struct lockdep_map lockdep_map;
+	u64 diskseq;
 };
 
 /*
@@ -332,6 +333,7 @@ static inline void bd_unlink_disk_holder(struct block_device *bdev,
 #endif /* CONFIG_SYSFS */
 
 dev_t part_devt(struct gendisk *disk, u8 partno);
+void inc_diskseq(struct gendisk *disk);
 dev_t blk_lookup_devt(const char *name, int partno);
 void blk_request_module(dev_t devt);
 #ifdef CONFIG_BLOCK